Digital images are known in the art and typically comprise a representation of a two-dimensional image as a finite set of digital values (often denoted as picture elements or pixels). Such a digital image typically contains a fixed number of rows and columns of pixels. Pixels are essentially small picture areas that contain quantized values that represent the brightness at various points of the image. Typically, these pixels are stored in computer memory as a so-called raster image or raster map that typically comprises a two-dimensional array of small integers.
Wide-angle images are also known in the art. Wide-angle lenses typically comprise a lens whose focal length is substantially shorter than the focal length of a more normal lens. Such a lens typically yields an extremely wide, hemispherical image and can serve to facilitate capturing a relatively broad field of view. At least some wide-angle lenses, such as so-called fisheye lenses, do not produce a rectilinear image. When working with digital images in a digital realm, however, it is possible to mathematically compensate for such distortion to thereby present a user with a compensated image comprising an essentially rectilinear image.
While such prior art techniques tend to be successful with respect to yielding a non-distorted rendered image, such prior art approaches tend to be relatively mathematically intensive. For some application settings, this requirement poses no special burden. For other application settings, however, such as when facilitating so-called pan/tilt/zoom functionality in a digital context, such computational requirements can become burdensome or even a point of failure. This, in turn, can result in unacceptably slow or even incomplete image manipulation.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein.